UCLA has a mature small animal imaging program based on micro-positron emission tomography, x-ray micro computed tomography, in-vivo bioluminescence and digital whole body autoradiography imaging. Central to this program, is our small animal imaging resource (SAIR), which provides service and support through a state of the art facility to more than 24 independent Principal Investigators funded through the NIH and other agencies. Most of the research projects of these investigators are focused in cancer diagnosis and therapy. In addition to this service component, the roles of the SAIR within the UCLA and the US environments are to: (a) educate students, post-doctoral scholars, physicians and other biology researchers from within and outside UCLA in the tools, technologies and applications of imaging, and (b) foster collaborations and develop new technologies and methodologies that will improve the quantitative capabilities of non-invasive imaging. These goals will hopefully lead to better understanding of human disease and might lead to better methods for diagnosis and treatment of cancer. As part of this SAIR proposal, besides the research support and education, two developmental projects are included, that should improve the quality and quantitative accuracy of the acquired data, while they reduce the impact from radiation exposure on the studied subjects. The first project will seek to standardize the animal handling and care part of the imaging protocol prior to, during and after the procedure, such that the animal's response is as uniform as possible. The second project seeks to estimate at first, secondly optimize and thirdly track the radiation exposure to the animal subjects throughout sequences of multiple imaging experiments that can last several months. Both these projects will greatly benefit not only the research experiments carried through the UCLA SAIR, but all preclinical research in the US.